1. Field of the Invention
The present invention relates to a device for detecting a placement position of a document, and more particularly to a method for detecting if the document is placed in a tilting manner, and a device that may perform the above-mentioned detection method and may let the document be fed at a correct document feeding angle.
2. Description of the Related Art
A conventional document feeder in accordance with the prior art is provided with a document guide plate, and a fixed sensor (microswitch). Thus, after the document is placed on the document guide plate, and enters the document feeder, the sensor may be triggered, to drive a document feeding roller to feed the document.
The document guide plate of the above-mentioned device is provided with two movable racks that may be moved relative to each other. The document is placed between the two movable racks. Thus, before use, it is necessary to adjust the relative distance between the two movable racks, thereby facilitating placing the document and correcting the angle of the document.
In the practical use, the user usually first place the document between the two movable racks, and then adjust the relative distance between the two movable racks. At this time, the document may be placed in a tilting manner, and may trigger the sensor at the fixed position, so that the document feeding roller is rotated to feed the document. Thus, for the scanning device, the scanning device will scan an d obtain a tilting image, or the document is jammed, thereby breaking the original document.
The present invention is to provide a method for detecting a placement position of a document. The purpose is in that, the automatic document feeding action is performed only after detecting the document is exactly placed at a correct angle.
The present invention is to provide a device for detecting a placement position of a document. The purpose is to efficiently perform detection of placement of the document, thereby preventing the document from being fed in a tilting manner.
The principle of design of the present invention is in that, the sensor for detecting if the document is placed may change its position according to variation of the placing document width, thereby correctly detecting the placing angle of the document.
In accordance with the objective of the present invention, one embodiment of the present invention is a method for detecting a placement position of a document, for detecting if the document is placed in the document feeding device in a tilting manner, and for driving the document feeding action. The detection method includes the following steps:
a placing step, for placing the document into the document feeding device;
an adjusting step, for adjusting the document placement width of the document feeding device to correspond to the document width;
a triggering step, for triggering the at least two sensors of the document feeding device by the document; and
a document feeding step, for driving the document feeding roller on the document feeding device after all of the sensors are exactly triggered in the triggering step, so as to feed the document automatically.
In accordance with the objective of the present invention, one embodiment of the present invention is a device for detecting a placement position of a document, including:
a document feeder,
a document guide plate, mounted on one side of the document feeder, and having two movable racks that are capable of moving relative to each other;
a document feeding roller, mounted on the document feeder, and having a leading edge located adjacent to one side of the document guide plate; and
at least two sensors, each respectively connected to each of the two movable racks of the document guide plate, and each of the sensors being in parallel with the tangential direction of the leading edge of the document feeding roller.
Thus, after the document is placed in the document feeding device, the document may be fed only when all of the sensors are driven. Thus, the document may be fed along the correct angle, thereby obtaining a better scanning quality.